1. Field of the Invention
The present invention relates to the use as UV absorbers with affinity for textile fiber of compounds containing a certain structural unit responsible for UV absorption, and also a method for protecting human skin against harmful UV radiation and a method for protecting dyed textile material against fading, and also a method for increasing the UV protection factor UPF for textile material, also a laundry detergent and a laundry pre- and aftertreatment which include these UV absorbers with affinity for textile fiber and also—since some of these UV absorbers with affinity for textile fiber are novel—these novel substances themselves and also a process for preparing them and a textile material comprising these UV absorbers with affinity for fiber.
2. Description of the Background
The harmful effects on human skin of the UV content of sunlight are not restricted to premature skin aging and the formation of erythemas (skin reddening, sunburn). Excessively long and intensive exposure of the skin to UV radiation also raises the risk of developing skin cancer. The chief culprit responsible for skin reddening and the increased risk of skin cancer is the UV-B range of UV radiation, i.e., the range from 280 to 320 nm. The peak of the erythema action spectrum is located at 308 nm.
Textiles absorb UV radiation and so act as a physical barrier to protect the skin against the harmful effects of sunlight (“textile skin protection”). However, the skin-protecting effect of textiles is dependent on many factors such as fiber type, fabric construction, fabric weight, color, moisture content or nature of finish. Summer clothing in the form of lightweight and light-colored cotton textiles offers only slight and hence inadequate protection against UV radiation.
It is mainly customary optical brighteners which have hitherto been used to finish and protect the textiles themselves and also for textile skin protection, especially stilbene- and triazine-based optical brighteners as described for example in EP-A 682 145, GB-A 2 313 375 or EP-A 728 749. But the agents are still in need of improvement with regard to their efficacy and possess a number of disadvantages.
It is an object of the present invention to provide UV absorbers which have affinity for fiber, which are improved in their efficacy and which are free of the disadvantages of the prior art.